My general tactics for the Amurites would be as follows.
Use any expedient technologies and religions to secure a small/medium empire with a good economy in the early game. Don't expand too fast or look for conflicts. Then concentrate on magic research to get Govannon, wizards, and firebows too. Use meta-magic to repeatedly change your mana nodes and get most the powerful magic promotions on your units. Govannon helps with this. Firebows and wizards can then form the core of a very capable mid game army. From now on you can look to expand militarily. Continue that military strategy through to have endgame armies with any big value units supporting your archmages, liches, and druids. Use any appropriate civics or religions, although you may lose druids if you lose neutrality, or lose mana types in the overcouncil.
If you don't understand magic promotions then you're not going to get the best out of the Amurites. The best way to learn is probably to play the Amurites and really test everything out. You can specialise, generalise, and try out every type of mana - all in one game. Govannon is the key to powerplaying the Amurites.